Pistachio rootstock named clone &#39;ucb1-d110&#39;

ABSTRACT

Disclosed is a new and distinct variety of pistachio rootstock called ‘UCB1-D110’ characterized in that, when compared to the industry standard ‘UCB1-D1’ rootstock, it has greater growth and tolerance to the soil salts of sodium sulfate and sodium bicarbonate; greater growth and tolerance to high levels of dissolved salts in irrigation water; and earlier vegetative bud break.

Latin name: Pistacia atlantica×Pistacia integerrima.

Varietal denomination: ‘UCB1-D110’.

BACKGROUND OF THE NEW VARIETY

The present invention comprises a new and distinct cultivar of hybridpistachio (Pistacia atlantica×Pistacia integerrima) used as a rootstockknown by the varietal name, clone ‘UCB1-D110.’ The clone, ‘UCB1-D110,’is an in vitro, single selection of the segregating controlled cross of(P. atlantica×P. integerrima) made at Foundation Plant Services,University of California, Davis. The purpose of the selection programwas to develop rootstocks with superior tolerance to soil salts.Seedlings were tested in salt trials in the laboratory and compared tothe ‘UCB1-D1’ rootstock. Those seedlings that exhibited high toleranceto various soil salts were selected. The new variety exhibits hightolerance to numerous, common salts found in the soil and irrigationwater.

The following characteristics distinguish ‘UCB1-D110’ from the industrystandard, ‘UCB1-D1’ rootstock:

-   -   1. Greater growth and tolerance to the soil salts, sodium        sulfate and sodium bicarbonate.    -   2. Greater growth and tolerance to high levels of dissolved        salts in irrigation water.    -   3. Earlier vegetative bud break.

ORIGIN AND ASEXUAL REPRODUCTION OF THE NEW VARIETY

Asexual reproduction of the new and distinct variety of rootstock wasaccomplished by germinating seed in vitro under aseptic conditions andpropagating the resulting seedlings using micropropagation techniques.Shoot epicotyl and hypocotyl tissue were collected from germinatingseedlings and placed on a standard growth media to produce shoots. Theshoots were sub-cultured and multiplied until desired numbers wereobtained and then transferred to standard rooting media for rooting.Rooted plantlets were transferred to a peat:perlite media in acclimationchambers under 100% humidity. Field environmental parameters weregradually introduced to harden plantlets which were then successivelytransferred to larger pots in the greenhouse as their size increased.These potted trees were used to establish field performance trials.Subsequent evaluations have shown those asexual reproductions aretrue-to-type to the original rootstock selection. All characteristics ofthe original tree were established and appear to be transmittedcompletely through succeeding asexual propagations.

SUMMARY OF THE NEW VARIETY

The clone ‘UCB1-D110’ rootstock is characterized by its tolerance tohigh levels of the soil salts, sodium sulfate, and sodium bicarbonate.In each case, clone ‘UCB1-D110’ had greater growth in laboratory salttrials than the industry standard rootstock, ‘UCB1-D1.’ In anotherlaboratory salt trial, media was supplemented with the total salt loaddetected in San Joaquin Valley irrigation water and also supplementedwith twice that load. In all cases, growth of ‘UCB1-D110’ outperformedthat of ‘UCB1-D1’ in the presence of high salts. In addition, vegetativebud break of ‘UCB1-D110’ was observed to be approximately 2 days earlierthan ‘UCB1-D1.’

DESCRIPTION OF THE ILLUSTRATIONS

The accompanying photographic illustrations show typical specimens ofvegetative growth of the new variety, with the color being as nearlytrue as is possible with color illustrations of this type:

FIG. 1 shows a 4 year pistachio tree of the new variety.

FIG. 2 shows a close-up of the mature leaves of the new variety.

DESCRIPTION OF THE NEW VARIETY

The following detailed description sets forth the characteristics of thenew variety. The data which defines these characteristics was collectedunder natural daylight on plants grown in the central valley ofCalifornia in Stanislaus County in the greenhouse and in the field.Descriptions may vary in slight detail due to climatic, soil andcultural conditions under which the variety may be grown. Colordesignations are presented with reference to the Inter-Society ColorCouncil, National Bureau of Standards, except where common color namesare also included.

-   Tree: Trunk circumference 1 foot off the ground is 27.4 cm. Trunk    lenticels are approximately 2.9 mm in length and 0.9 mm in width.    Trunk lenticels are linear in shape. Trunk lenticel color is strong    brown [55. s.B]. Trunk lenticels number approximately 43 per square    inch. Bark color is dark grayish yellow [91. d.g.Y]. Branch    lenticels are approximately 1.6 mm in length and 1.0 mm in width.    Branch lenticels are elliptic in shape. Branch lenticel color is    strong brown [55. s.B]. Branch lenticels number approximately 45 per    square inch.-   Vegetative buds:    -   -   Size.—Approximately 43 mm in length and 4 mm in width.        -   Shape.—Conical.        -   Color.—Brilliant, yellowish green [130. b.y.G] with strong,            orange yellow [68. s.OY] exterior basal scales. As tips            unfurl they become strong purplish red [255. s.p.R]. First            vegetative buds of ‘UCB1-D110’ opened approximately 2 days            earlier than ‘UCB1-D1.’Leaflet blade color on the top and            bottom surfaces is vivid red [11. v.R]. At the junction of            the base of the petiole with the rachis, tissue color is            brilliant, yellowish green [130. b.y.G]. Expanding rachis            color is brilliant, yellowish green [130. b.y.G] at the            extreme tip and very dark purplish red [260. v.d.p.R] on all            sides elsewhere. Leaf venation pattern is pinnate and            alternate. Midrib and veins are brilliant, yellowish green            [130. b.y.G].-   Foliage: Leaves are pinnately compound composed of alternate    leaflets numbering between 10 and 19. Compound leaf size variations    are great but average approximately 57 cm in length and 41 cm in    width at the widest point. Young leaflets are glossy and dark    grayish red [20. d.g.R] on upper surfaces and moderate olive green    [125. m.OG] on lower surfaces. Older leaflet surfaces are strong    olive green [123. s.OG] on upper surfaces and moderate olive green    [125. m.OG] on lower surfaces. Leaflet shape is lanceolate with an    acute apex and cuneate base. There is great variation in leaf and    leaflet size depending on the time of the season, position on the    tree and tree age. Leaflet size varies considerably but averages 78    mm in length and 26 mm in width. Leaf venation pattern is pinnate    and venation is brilliant yellowish green [130. b.y.G]. The midrib    is prominent and in very young tissue is dark grayish red [20.    d.g.R] becoming brilliant yellowish green[130. b.y.G] as tissue    becomes older. Leaf margins are entire and surfaces are glabrous.    Petiole and rachis upper and lower surface colors are the same which    is predominately strong purplish red [255. s.p.R] with some strong    yellowish green [131. s.y.G] streaking on lower surfaces. Petiole    length varies considerably but averages 47 mm in length from point    of rachis attachment to basal leaflet, and is glabrous with no    wings. Rachis length varies considerably and averages about 43 cm in    length.-   Salt tolerance: Different concentrations of individual salts that    contribute to soil salinity and alkalinity ranging from 0 to 10,000    mg/1 were added to the culture medium that rootstock was growing in.    Each clone-salt combination was replicated four times. Observations    were taken on visual injury symptoms and growth measured by number    of shoots and leaves per plant. ‘UCB1-D110’ rootstock is    characterized by its tolerance to high levels of the soil salts,    sodium sulfate (at 10,000 mg/l) and sodium bicarbonate (at 1,000    mg/1). As measured on a growth scale of 1 to 10, in the case of each    of these salt trials ‘UCB1-D110’ had greater growth than the    industry standard rootstock, ‘UCB1-D1.’ In another salt trial, media    was supplemented with the comparable total salt load detected in San    Joaquin Valley irrigation water (Sanden, B. et al. 2009. Large-Scale    Utilization of Saline Groundwater for Irrigation of Pistachios    Interplanted with Cotton. 2009 Progress Rpt. of CA Pistachio Comm.)    plus twice the detected salt load. In all cases, growth of    ‘UCB1-D110’ outperformed that of ‘UCB1-D1’ in the presence of high    soluble salts.

Having thus described and illustrated the new variety of rootstock, whatis claimed as new and desired to be secured by plant letters patent is:1. A new and distinct variety of pistachio rootstock substantially asillustrated and described called ‘UCB1-D110’ characterized in that, whencompared to the industry standard ‘UCB1-D1’ rootstock, it has greatergrowth and tolerance to the soil salts of sodium sulfate and sodiumbicarbonate; greater growth and tolerance to high levels of dissolvedsalts in irrigation water; and earlier vegetative bud break.